(a) Field of the Invention
The present invention is related to a light emitting diode (LED), and more particularly, to one that promotes luminance performance by reducing light source loss.
(b) Description of the Prior Art
FIG. 1 shows a schematic view of an SMD LED of the prior art, the LED 1 is comprised of a housing 11, an accommodation space 113 enclosed by a first side 111 and a second side 112 of the housing 11; a light emitting chip 12 is placed on a bottom of the accommodation space; two separately provided lead frames 13, 14 are disposed in the housing 11; the light emitting chip 12 disposed on the lead frame 13 is electrically connected to both lead frames 13, 14 respectively by means of a conductor 15; and a colloid is finally packed in the accommodation space 113 to complete a structure of the LED 1.
Certain portion of streams of light emitted from the light-emitting chip 12 upon entering into where two different types of media of air and the packed colloid present will be reflected back to the packed colloid 16 and prevented from entering into the ambient air. Some of those streams of light re-entering the packed colloid 16 are reflected onto while others are reflected into the first and the second sides 111, 112 due to total reflection. Whereas both the first and the second sides 111, 112 are of greater inclinations, i.e., an included angle defined respectively by the bottoms of the first and the second sides 111, 112 are greater. Accordingly, those streams of light re-entering the first and the second sides 111, 112 can be easily reflected again into a bottom of the accommodation space 113 without effectively leaving the accommodation space 113 to result in loss of streams of light, reduced use efficiency of streams of light, and poor luminance performance of the LED.
An improvement has been attempted to provide smaller inclinations for the first and the second sides, i.e., a smaller and more inclined included angle defined respectively by both first and second sides and the bottom of the accommodation space for those streams of light reflected from the packed colloid to emit towards where above the accommodation space. However, both the first and the second sides disposed in the accommodation space at greater inclinations result in smaller area of the bottom of the accommodation space and larger area at an opening of the accommodation space to make it very difficult in properly locating both of the light-emitting chip and the conductor.